JP2019508697A - Device, system and method for measuring the internal impedance of a test battery using frequency response - Google Patents

Abstract

Disclosed are battery impedance testing devices, circuits, systems, and related methods. The impedance measuring device includes a current driver configured to generate an excitation current signal applied to the test battery in response to the control signal, and a processor operably coupled to the current driver. The processor is configured to generate control signals during the autoranging mode and the measuring mode. In autoranging mode, excitation current signals are applied to the test battery over a plurality of different amplitudes to measure the response to the excitation current signal at each amplitude. In the measurement mode, an excitation current signal is applied to the test battery with an amplitude responsive to the result of the autoranging mode. For low impedance batteries, improved sensitivity and resolution can be achieved in conjunction with rapid measurement times. [Selected figure] Figure 5

Description

Priority claims The present application is a device, system, and method for measuring the internal impedance of a test battery using a frequency response, which is a pending "Device, System, and Method for Measuring Internal Impedance of a Test Battery Using Frequency Response". And claim the right of filing date of US patent application Ser. No. 15 / 060,183, filed Mar. 3, 2016. By citing this patent application herein, the entire disclosure content is hereby incorporated by reference.

RELATED APPLICATIONS This application is related to pending US Patent Application No. 14/296, 321, filed June 4, 2014, and published as US2014 / 0358462. U.S. Patent Application No. 14 / 296,321 claims the benefit of U.S. Provisional Patent Application No. 61 / 831,001, filed June 4, 2013. The present application is also related to copending US patent application Ser. No. 14 / 789,959, filed Jul. 1, 2015. The disclosure of each of the above patent applications is hereby incorporated herein by reference in its entirety.

STATEMENT present invention relates to federal support research or development, under the awarded by the US Department of Energy Contract No. DE-AC07-05-ID14517, was carried out by government support. The government has certain rights in the invention.

FIELD Embodiments of the present disclosure relate to devices, systems, and methods for impedance measurement of energy storage cells, such as electrochemical cells, and more particularly to analysis of the state of health of energy storage cells. .

  Chemical changes to the electrodes in a rechargeable battery can cause degradation of battery capacity, duration of charge retention, charging time, and other functional parameters. Battery degradation can build up over the life of the battery. Environmental factors (eg, high temperatures) and functional factors (eg, improper charging and discharging) may also accelerate battery degradation. Operators of systems that rely on rechargeable battery power may wish to monitor the degradation of the batteries that they use. One of the battery degradation indicators is an increase in battery impedance.

  FIG. 1 is a plot 102 of the impedance of a fresh battery, and a plot 104 of the impedance of the aged battery, at various different frequencies using an electrochemical impedance measurement (EIM) system. It is measured. The Y-axis is the imaginary impedance for several different frequencies plotted in FIG. 1 and the X-axis is the real impedance. As shown in FIG. 1, the aged battery (plot 104) exhibits higher impedance than the new battery (plot 102) at each of the different frequencies. System operators who rely on rechargeable batteries may use impedance data, such as the impedance data of FIG. 1, to determine that battery replacement is required before a failure occurs. it can. Such proactive replacement can prevent costly delays and equipment damage that may occur in the event of a battery failure. Also, knowledge of the battery's continued reliability can prevent the expense associated with unnecessarily replacing a battery that still has a significant remaining lifetime.

  Existing impedance measurement systems have a resolution of about 0.1 milliohms when operating in an excitation current range of about 500 mA. As a result, existing impedance measurement systems could be determined with reasonable resolution provided that the impedance of the test battery exhibits an internal impedance of 10 milliohms. The resolution of existing impedance measurement systems may limit the ability to test batteries exhibiting lower internal impedance (e.g., 1 milliohm). Some other impedance measurement methods (eg, electrochemical impedance spectroscopy) achieve high resolution, but it takes too long to tune, for example, it takes about 10 minutes to obtain measured values ( slow) there is a case.

  Disclosed herein are impedance measuring devices. The impedance measuring device includes a current driver configured to generate an excitation current signal applied to the test battery in response to the control signal, and a processor operably coupled to the current driver. The processor is configured to generate control signals during an auto-ranging mode and a measurement mode. In autoranging mode, an excitation current signal is applied to the test battery over a plurality of different amplitudes, and the response to the excitation current signal is measured at each amplitude. In the measurement mode, an excitation current signal is applied to the test battery with an amplitude responsive to the result of the autoranging mode.

  In one embodiment, an impedance measurement system is disclosed. The impedance measurement system includes a test battery and an impedance measurement device operably coupled to the test battery. The impedance measurement device is operatively coupled to a preamplifier including a current driver and a test battery and a signal measurement module operably coupled, a current control signal generator operatively coupled to the preamplifier, and the preamplifier And a processor operatively coupled to the current control signal generator and the data acquisition system. The processor controls the current control signal generator to send a current control signal to the preamplifier during the autoranging mode to cause the current driver to generate an excitation current signal exhibiting an amplitude range, and to measure the signal during the autoranging mode Control the data acquisition system to analyze the test battery response from the module, send a current control signal to the preamplifier during measurement, and at least partially analyze the test battery response during autoranging mode Control the current control signal generator to cause the current driver to generate an excitation current signal exhibiting a selected amplitude, and analyze the test battery response from the signal measurement module during the measurement mode to test the test battery Configured to control the data acquisition system to determine the impedance of the That.

  In one embodiment, a test battery impedance measurement method is disclosed. The method comprises the steps of applying an excitation current signal to the test battery comprising a plurality of pulses exhibiting different amplitudes during the autoranging mode and measuring an electrical signal from the test battery in response to the excitation current signal over the plurality of different amplitudes. And applying an excitation current signal to the test battery which exhibits a fixed amplitude during the measurement mode, the fixed amplitude being at least partially based on an analysis of the electrical signal measured during the autoranging mode. Measuring the electrical signal from the test battery in response to the excitation current signal exhibiting a fixed amplitude during the measurement mode to determine the internal impedance of the test battery.

FIG. 1 is a new battery impedance plot and an aged battery impedance plot measured at various different frequencies using an electrochemical impedance measurement system. FIG. 2 is a simplified block diagram of an impedance measurement system configured to perform real time impedance spectrum measurement of a test battery, in accordance with an embodiment of the present disclosure. FIG. 3 is a simplified block diagram of selected features from the impedance measurement device of the impedance measurement system of FIG. FIG. 4 is a simplified block diagram of the current driver of FIG. FIG. 5 shows a circuit diagram of the signal measurement module of the preamplifier of FIGS. 2 and 3. FIG. 6 is a flow chart illustrating a method of operating a battery impedance measurement system in accordance with an embodiment of the present disclosure.

  The following detailed description refers to the accompanying drawings. The accompanying drawings form a part of the specification and, as such, show by way of illustration specific embodiments in which the present disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present disclosure. However, it should be understood that the detailed description and the specific examples, while indicating examples of embodiments of the present disclosure, are given by way of illustration and not limitation. From the present disclosure, various substitutions, alterations, additions, rearrangements, or combinations thereof that fall within the scope of the present disclosure can be made by those skilled in the art and will be apparent to those skilled in the art.

  By convention, the various features shown in the drawings may not be drawn to the same scale. The figures presented herein are not intended to be an actual view of any particular device (eg, device, system, etc.) or method, and are merely representative of various aspects of the disclosure. It is merely an ideal representation employed to describe the embodiment. Thus, the dimensions of the various structures may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may be simplified for the sake of clarity. That is, the drawings neither illustrate all of the components of a given apparatus nor illustrate all of the operations of a particular method.

  The information and signals described herein may be expressed using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout this description may be voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any of these. It may be expressed in combination. For clarity of presentation and explanation, certain drawings may exemplify the signal as a single signal. It should be understood by those skilled in the art that a signal may represent a bus of a signal. In this case, the bus can have various bit widths, and the present disclosure can be implemented on any number of data signals, including one data signal.

  The various exemplary logic blocks, modules, circuits, and algorithmic acts described in connection with the embodiments disclosed herein are implemented as electronic hardware, computer software, or a combination of both. can do. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and acts will be described generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. One skilled in the art could realize the described functionality in various ways for each particular application, but such implementation decisions are within the scope of the disclosed embodiments described herein. It should not be interpreted as causing a deviation.

  In addition, it is noted that embodiments may be described in terms of processes illustrated as a flow chart, a flow diagram, a structure diagram, or a block diagram. Although the flowchart may describe operational acts as a continuous process, many of these acts may be performed in another sequence, performed in parallel, or performed substantially simultaneously. Can. In addition, the order of acts may be rearranged. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram or the like. Furthermore, the methods disclosed herein may be implemented in hardware, software, or both. If implemented in software, the functions may be stored or transmitted as one or more computer readable instructions (eg, software code) on a computer readable medium. Computer-readable media can include both computer storage media and communication media, which includes any media that facilitates transfer of a computer program from one place to another. Computer readable media are, for example, hard drives, disk drives, magnetic tapes, CDs (compact disks), DVDs (digital versatile disks or digital video disks), solid state storage devices (solid state storage) And volatile and non-volatile memory, such as, for example, magnetic and optical storage devices, such as drives) and other similar storage devices.

  In the present specification, when referring to elements using designations such as "first", "second", etc., any limitation on the quantity or order of these elements must be explicitly stated. For example, it should be understood that it is not so limited. Conversely, such designations can be used herein as a convenient way of distinguishing between two or more elements, or instances of one element. That is, when referring to the first and second elements, it does not mean that only two elements need to be used there, but that for some reason the first element must precede the second element It is not to do. Also, unless otherwise stated, a set of elements can include one or more elements. For example, when describing a circuit element such as a resistor, capacitor, or transistor, the circuit element's designator begins with the element type code (eg, R, C, M), and is followed by a numeric indicator. Continues.

  As used herein, the terms "energy storage cell" and "energy storage cells" refer to chemical energy applied between the positive and negative terminals of the energy storage cell. Refers to a rechargeable electrochemical cell that converts to a voltage potential. The terms "battery", "cell" and "battery cell" may each be used interchangeably with the term "energy storage cell" herein.

  As used herein, the term "mid-range voltage" means a voltage that is in the range of around 50V. That is, the mid-range voltage can include an average voltage of about 40 V to about 60 V, with a variation of about 90% to 99%, depending on the tolerance desired for a given system.

  As used herein, the term "high-range voltage" means a voltage in the range of around 300 volts. That is, the high voltage can include an average voltage of about 250 V to 350 V, with a variation of about 90% to 99%, depending on the tolerance desired for a given system.

  As used herein, the terms "sinusoid" and "sinusoidal" are electrical signals that oscillate with the passage of time, at least substantially in accordance with a sine or cosine function (eg, Current and voltage potential) (eg, with various magnitudes and phase shifts). As will be readily appreciated by those skilled in the art, any given sinusoidal signal can be equivalently represented as either a sine or cosine function. Because sine and cosine are merely out of phase with each other. Sinusoidal signals are disclosed herein as being applied to energy storage cells and shunts (e.g., resistors of known resistance value for calibration purposes). In some cases, these sinusoidal signals may be more specifically referred to herein as either sinusoidal or cosine signals. These specific references to sine and cosine signals are as follows: a sine wave signal was first asserted on a conductive line (eg, the positive or negative terminal of a battery, a lead trace on a circuit board, a wire, etc.) It is also possible to indicate the phase of such a signal with respect to the moment.

  As used herein, the term "sum of sine waves" ("SOS") refers to an electrical signal that oscillates according to the sum of sine wave signals. The SOS signal can include a summation of sine signals, a summation of cosine signals, or a combination thereof. For example, a harmonic orthogonal synchronous transform (HOST) SOS signal can include a fundamental sinusoidal signal having a fundamental frequency and one or more sinusoidal signals added thereto. The one or more sinusoidal signals have continuous integer harmonic frequencies of the fundamental frequency and alternate between sinusoidal and cosine signals (or any out of phase version thereof) for each successive harmonic. The orthogonality of the harmonic sinusoidal signals summed together at the HOST SOS can serve to reduce or eliminate excessive transients. Although SOS signals are cited herein to illustrate examples, embodiments of the present disclosure use other types of excitation signals, including alternating sines, cosines (ASC) summation signals. It is also assumed.

  FIG. 2 is a simplified block diagram of an impedance measurement system 200 configured to perform real-time impedance spectrum measurements of the test battery 205, in accordance with an embodiment of the present disclosure. Test battery 205 refers to the battery under test and may be the actual battery deployed and used by the end user. The impedance measurement system 200 can include an impedance measurement device (IMD) 200 (sometimes referred to as an impedance measurement box (IMB)) operably coupled to the test battery 205. The IMD 210 can include a processor 212, a data acquisition system (DAS) 214, an SOS generator (SOSG) 216, a preamplifier 218, and a power supply 222. The IMD 210 can be used to monitor battery health in the field, even in a variety of different environments and battery types. As an example, impedance measurement system 200 may be incorporated into a car or other vehicle having a battery that includes one or more energy storage cells. Such vehicles may include electric vehicles or hybrid vehicles. Also, embodiments of the present disclosure may be employed in applications other than vehicles, such as by being associated with an energy storage cell operably coupled to a solar, wind, wave energy generation system, as a non-limiting example. Is also conceivable.

  The SOSG 216 can be configured to generate an SOS control signal to the preamplifier 218 to control the SOS current signal output by the preamplifier 218. The SOS control signal may be selected to cause the preamplifier 218 to provide an SOS current signal that includes the sum of a plurality of different current signals having a plurality of different target frequencies to test the impedance of the test battery 205. In one embodiment, the SOS control signal may include a voltage signal that is proportional to the current desired for the SOS current signal output by the preamplifier 218. Thus, the SOS control signal can include the SOS voltage signal. Here, using the SOS signal as an example, the SOSG 216 may be an excitation current control signal generator configured to control other types of excitation current signals applied to the test battery 205. That is, the SOS signal is used here as a non-limiting example of a signal that can be applied to the test battery 205.

  The IMD 210 can be configured to measure the electrical signal 206 at the terminals of the test battery 205 in response to the SOS current signal applied to the terminals of the test battery 205. The preamplifier 218 can be configured to measure a battery response signal (eg, a voltage response and / or a current response) in response to receiving the electrical signal 206 from the test battery 205. The DAS 214 can be configured to receive the battery response signal and calculate the impedance of the test battery 205 at the frequency of the SOS control signal. In this manner, IMD 210 can be configured to test the impedance of test battery 205 at a plurality of different frequencies substantially simultaneously.

  In one embodiment, DAS 214 may also divide the measured voltage response by the measured current response to determine the impedance response of test battery 205. In such an embodiment, the impedance of the test battery 205 can be determined by dividing the measured voltage by the measured current, thus eliminating the need for calibration. In one embodiment, DAS 214 may also be configured to measure only the voltage response of test battery 205 to SOS current signal 356 (FIG. 3). In such embodiments, calibration may be required to determine the impedance of the test battery 205. A variety of calibration methods (eg, single-shunt calibration, multiple shunt calibration, etc.) that can be used to take into account the real and imaginary parts of the signal are considered Be In the single shunt method, the standard deviation of the measured value over time can be determined, and then the ratio of the measured value to the standard deviation of the known single shunt resistance over time is expressed by the equation (equate ) To determine an unknown shunt resistance.

  The IMD 210 can utilize data processing methods (e.g., an algorithm) to generate battery impedance spectral data 225. Impedance spectrum data 225 may be transmitted from IMD 210 to remote computer 230. The impedance spectrum data 225 can be formatted in any suitable format (eg, comma separated value (CSV) format). Each spectrum includes a time stamp and an information header, and impedance spectrum data 225 may include frequency, real part of impedance, imaginary part of impedance, and common mode battery voltage for that spectrum. Additional data that may be sent to remote computer 230 along with impedance spectrum data 225 includes SOS RMS current, and magnitude and phase calibration constants. Remote computer 230 may include a personal computer, a tablet computer, a laptop computer, a smart phone, a server, a vehicle computer (e.g., a central processing unit), or other suitable computing device.

  Users may use Universal Serial Bus (USB) interface, hard-wire serial interface, hard-wire parallel interface, wireless interface (eg WiFi, ZIGBEE®, BLUETOOTH®), or others The IMD 210 can be controlled from the remote computer 230 using commands 235 via an interface, such as a suitable interface. For example, IMD 210 can be entered via the human interface on remote computer 230 or IMD 210 for the purpose of entering control constraints into IMD 210, performing embedded system diagnostics, performing calibration, or performing manual impedance spectrum acquisition. It may be controllable. The IMD 210 can implement a minimum of three-point magnitude and phase calibration for each frequency in the SOS control signal.

  Processor 212 may be configured to synchronize and control DAS 214, SOSG 216, and preamplifier 218. In one embodiment, the measurements may be performed according to a set of schedules and / or control parameters commanded by remote computer 230. As a non-limiting example, processor 212 can interface with remote computer 230 to download desired parameters and commands and upload various measurement data. As a non-limiting example, the purpose of storing the desired number of battery impedance spectra so that the processor 212 or other device not shown, such as a memory, holds it until it processes the acquired battery response time record A suitable buffer memory can be included to hold on, to hold system control and interface software, to hold high resolution SOS samples, and to hold impedance spectral control parameters. Further, processor 212 is configured to receive the downloaded impedance spectrum control and calibration parameters and upload the stored battery impedance spectrum data to remote computer 230 under the direction of remote computer 230. You can also.

  In operation, when the measurement is performed, the DAS 214 sends a digital signal ("wake up") to the power supply 222, causing the power supply 222 to wake up the rest of the system (e.g., the preamplifier 218). Electrical signal 206 may be measured by preamplifier 218 and input to DAS 214 as an analog signal "battery voltage". At least one of DAS 214 or processor 212 can digitize the voltage, and the digitized result can be sent to remote computer 230. The remote computer 230 or at least one of the processors 212 then processes the measured DC battery voltage and uses the DAS 214 to generate a series of digital signals (e.g. "Buck Signal", "Buck D / B A control, etc.) can be sent to the preamplifier 218 to generate a DC bias voltage that is subtracted from the DC voltage response from the overall response of the test battery 205. As discussed further below with reference to FIG. 5, low back and high back signals can be generated to achieve higher gain signals and use them to improve measurement resolution.

  A preamplifier 218 is connected to the test battery 205, and at least one of the remote computer 230 or processor 212 sends measurement signals to the preamplifier 218, such as, for example, SOS control signals or other suitable measurement signals. When the test battery 205 is excited by the SOS current, the voltage appearing at its terminal may be a value obtained by adding any voltage drop of the SOS current acting on the internal impedance of the test battery 205 to the battery voltage. It is this SOS voltage drop that yields a spectrum of battery impedance to the test battery 205 when captured and processed. The challenge would be that the battery voltage could be two orders of magnitude greater than the SOS voltage drop. That is, in order to detect this signal with high accuracy, it is sufficient to subtract the battery voltage before measuring the SOS voltage drop, and all the resolution bits of the A / D converter concentrate on the desired signal and the accuracy is greatly increased Make it possible to This subtraction of battery voltage is accomplished by measuring the battery voltage prior to application of the SOS current, then feeding back the computer generated buck voltage and subtracting this buck voltage from the total battery voltage by the differential amplifier, SOS Only the voltage can be obtained.

  In one embodiment, SOSG 216 may be configured to synthesize the sample clock used by DAS 214 under control of processor 212. The sample clock frequency can be selected at a rate that may differ depending on the data processing method used. The SOSG 216 can have programmable signal levels for the DAC output to the smoothing filter 306 (FIG. 3), which allows the processor 212 to control the SOS RMS current level to the test battery 205. Become. The SOSG 216 can be configured to operate in the auto-range mode as well as in the measurement mode under the control of the processor 212. The autoranging mode may be performed to determine the SOS current amplitude to be used for the SOS current during the measurement mode prior to the measurement mode. The autoranging mode and the measurement mode are discussed further with respect to FIG. 6 below.

  The DAS 214 can be configured to receive an external sample clock from the SOSG 216 with a desired resolution (eg, 16 bits, 32 bits, etc.), for example, a clock frequency that can range from 1 kHz to 100 kHz. The DAS 214 may receive an enable signal from the processor 212 and may begin acquiring data simultaneously with the application of the SOS current signal to the test battery 205 to be tested during its autoranging mode or its measurement mode. The DAS 214 can accept an analog battery voltage signal conditioned for digitization by the preamplifier 218. The DAS 214 can include buffer memory to hold and upload samples of the digitized battery voltage signal to memory (not shown). Each of the acquired samples can be part of a time record array input to a data processing method. In addition, the DAS 214 can obtain a measurement of the DC voltage and the case temperature of the test battery 205 prior to application of the SOS current.

  In one embodiment, the SOS current leads are configured as twisted wire pairs and may be fuse protected. The preamp 218 can utilize full differential battery voltage sense and can incorporate a method of biasing out common mode battery voltage from battery response to SOS current excitation . It can be said that this biasing allows the maximum resolution of the DAS 214 to be concentrated on the test battery's response to the SOS current rather than the average battery voltage.

  The input signal to preamplifier 218 may be a zero order hold SOS control signal from SOSG 216. The preamp 218 includes an active Butterworth lowpass filter as the smoothing filter 306 (FIG. 3), with approximately 1 dB of attenuation at 8 kHz, and the frequency introduced by the zero order hold upon SOS signal. Can have an attenuation of 60 dB. The SOS control signal may then be provided to the current driver 308 (FIG. 3), which converts the SOS control signal into a current (eg, “SOS current”) provided to the test battery 205. The signal measurement module 310 (FIG. 3) of the preamp 218 can detect the battery voltage and subtract the DC back voltage into a battery response, which can be digitized by the DAS 214. The resulting battery response can be used by the various data processing methods discussed herein to generate an impedance spectrum.

  In one embodiment, an optional connection circuit (not shown) is included between the preamp 218 and the test battery 205 to provide at least one signal line of the preamp 218 for supplying the SOS current signal with the test battery 205. Can also be separated from the DC voltage generated by As a result, it is not necessary to expose the sensitive electronic circuit included in the preamplifier 218 to the extremum of the DC voltage potential generated by the test battery 205. Also, the preamp 218 needs to receive less noise than if the analog ground extend outside the preamp 218. As a result, the connection to the test battery 205 can be disconnected when the SOS current signal is not sent to the test battery 205. An example of such an optional connection circuit using a relay coupled between the preamp 218 and the test battery 205 is filed on June 4, 2014, entitled "Apparatuses and Methods for Testing Electrochemical Cells by Measuring Frequency Response. U.S. Patent Application Publication No. 2014/0358462 entitled "Devices and Methods for Testing Electrochemical Cells by Measuring Frequency Response". As already mentioned above, the entire disclosure content of the present application is incorporated herein by reference.

  FIG. 3 is a simplified block diagram of selected features from IMD 210 of impedance measurement system 200 of FIG. As shown in FIG. 3, the IMD 210 may include an SOS control module 302, a digital to analog converter (DAC) 304, a smoothing filter 306, a signal measurement module 310, and an impedance calculation module 312. SOSG 216 may incorporate SOS control module 302 and DAC 304. The preamplifier 218 may incorporate the smoothing filter 306, the current driver 308, and the signal measurement module 310. The DAS 214 may incorporate an impedance calculation module 312.

  The SOS control module 302 can be configured to generate the digital SOS signal 350. The SOS signal 350 comprises the sum of sine waves having a plurality of different frequencies related to the impedance measurement of the test battery 205 (FIG. 2). Digital SOS signal 350 may be sampled at least at the Nyquist rate of the highest frequency of the plurality of different frequencies of digital SOS signal 350. Also, digital SOS signal 350 may represent at least one period of the lowest frequency of the plurality of different frequencies of digital SOS signal 350. SOS control module 302 may be configured to provide digital SOS signal 350 to DAC 304.

  DAC 304 may be configured to convert digital SOS signal 350 into an analog signal that is sent to preamplifier 318. It will be appreciated by those skilled in the art that digital signals such as digital SOS signal 350 can only manifest a discrete set of discrete signal levels. As a result, when digital signals are converted to analog signals, analog equivalents may exhibit step-like or "choppy" fluctuations. That is, the analog signal generated by the DAC 304 may be an uninterrupted SOS signal 352 exhibiting a step-like variation. This uninterrupted SOS signal 352 may be received by the smoothing filter 306 internal to the preamp 218. In one embodiment, smoothing filter 306 may be incorporated within SOSG 216.

  The smoothing filter 306 may be configured to "smooth" the choppy SOS signal 352 to provide a smooth SOS control signal 354. As a non-limiting example, the smoothing filter 306 may include a low pass filter configured to smooth out stair-step variations in the uninterrupted SOS signal 352. A smooth SOS control signal 354 can be provided to the current driver 308. In response to the smooth SOS control signal 354 being provided to the current driver 308, the current driver 308 can send a corresponding SOS current signal (FIG. 2) to the test battery 205.

  As will be appreciated by those skilled in the art, the filter can change the periodic signal magnitude, phase, or combinations thereof. It should also be appreciated that the filter can vary the magnitude and phase of different components of the signal oscillating at different frequencies in different ways. Thus, the magnitude, frequency, or a combination thereof of each of the different frequency components of the smooth SOS control signal 354 is at least partially smoothed from the corresponding magnitude and frequency of the different frequency components of the digital SOS signal 350. It can be varied by 306.

  In one embodiment, properties of the smoothing filter 306 may be known to analytically estimate the frequency response of the smoothing filter 306. In one embodiment, calibration can be used to determine the frequency response to the smoothing filter 306. SOS control module 302 uses the frequency response of smoothing filter 306 to predict changes in magnitude, phase, or a combination thereof that smoothing filter 306 is expected to impose on different frequency components of SOS control signal 354. Can be taken into account. When generating the digital SOS signal 350, the SOS control module 302 can compensate for these predicted changes. In other words, the SOS control module 302 can be configured to pre-emphasize the digital SOS signal 350 to compensate for the response of the smoothing filter 306. As one non-limiting example, if the smoothing filter 306 is expected to attenuate and shift the first frequency component of the uninterrupted SOS signal 352 by a known amount, the SOS control module 302 may determine the expected change. To compensate, the magnitude of the corresponding first frequency component of the digital SOS signal 350 can be increased and phase shifted by a known amount in advance.

  Signal measurement module 310 may be configured to measure electrical signal 206 at the terminals of test battery 250. As a non-limiting example, the signal measurement module 310 can be configured to measure the voltage response of the test battery 205 to the SOS signal, the current response of the test battery 205 to the SOS signal, or a combination thereof. Signal measurement module 310 may be configured to provide measurement signal data 360 to impedance calculation module 312 indicating the measurement response of test battery 205 to the SOS signal.

  The impedance calculation module 312 may be configured to calculate the determined impedance (impedance data 362) of the test battery 205 using the measured signal data 360 from the signal measurement module 310. As a non-limiting example, measurement signal data 360 may include both a voltage response and a current response of test battery 205 to SOS current signal 356 (FIG. 2). The impedance calculation module 312 may be configured to divide the voltage response by the current response to determine impedance data 362 for the plurality of different frequencies for the plurality of different frequencies of the SOS current signal 356.

  Also, as a non-limiting example, measurement signal data 360 may include only the voltage response of test battery 205 to SOS current signal 356. The impedance calculation module 312 can be configured to estimate the current response using the voltage response and calibration data from previous or future calibration of the control circuit. Measure a known calibration response by applying SOS current signal 356 to one or more shunts of known impedance and measuring and storing calibration data including the response of one or more shunts to SOS current signal 356 can do.

  Impedance calculation module 312 is configured to determine test battery 205 at each of the frequencies included in digital SOS signal 350 (ie, the same frequency included in broken SOS signal 352, SOS control signal 354, and SOS current signal 356). It may be configured to supply or store impedance data 362 that includes impedance. In one embodiment, impedance data 362 may be displayed to a user of impedance calculation system 200 (FIG. 2) (eg, in list form, graph form, table form, etc., on an electronic display of impedance measurement system 200). . In one embodiment, the impedance data 362 may be processed automatically to determine whether the test battery 205 should be replaced and the user may be notified of this automatic determination. In one embodiment, impedance data 362 may be automatically processed to determine an estimate of how much life is remaining in test battery 205. Such automated processing may be performed locally by impedance measuring system 200 and may be performed remotely by a computing device (eg, remote computer 230) configured to communicate with impedance measuring system 200. Or a combination of these. An alert (e.g., visual, audible, or a combination thereof) can also be emitted when IMD 210 detects that test battery 205 should be replaced.

  FIG. 4 is a simplified block diagram of the current driver 308 of FIG. In one embodiment, current driver 308 can include a differential current source. The differential current source includes a push current source 410 and a pull current source 420, which receive the SOS control signal 354 (eg, via the smoothing filter 306 (FIG. 3)) and are supplied to the test battery 205 It is configured to generate the SOS current signal 356. The SOS current signal 356 can include a current signal that is proportional to the voltage potential of the SOS control signal 354. As discussed above, the SOS current signal 356 may include the sum of sinusoidal current signals having a frequency related to the impedance measurement of the test battery 205.

The push current source 410 can be configured to push the current I _PUSH to the test battery 205, and the pull current source 420 can be configured to pull the current I _PULL from the test battery 205. The analog ground terminal GND of the current driver 308 is in a floating state between the push current source 410 and the pull current source 420, and the analog ground terminal GND can be separated from the terminal of the test battery 205. The push current source 410 and the pull current source 420 may be high impedance current sources. As a result, the SOS current excitation circuit can be completely high impedance ground isolated. As a result, the analog ground GND of the system can be moved into the interior of IMD 210 (FIG. 2) and shielded more strongly from noise than in many prior systems. In addition, the voltages of the current sources feeding the operational amplifiers 412, 422 can be balanced (eg, at ± 30 V), which can further reduce noise from the power supply 222 (FIG. 2). As a result of the voltage of the current driver 308 being balanced, it is possible to eliminate the need for a protector that protects the current driver 308 when the test battery 205 is reversely connected.

In certain embodiments, push-current source 410, a resistor _{R INA1, R INA2, R FA1} , R FA2 operational amplifier 412, and operatively coupled to the _{R SA,} may include an operational amplifier current source arrangement . Input resistors R _INA1 and R _INA2 may be operatively coupled to the inverting input and the non-inverting input of operational amplifier 412, respectively. The non-inverting input of the operational amplifier 412 can be configured to receive the SOS control signal 354 via the resistor R _INA2 . The inverting input of operational amplifier 412 may be operatively coupled to analog ground GND via resistor R _INA1 . The resistors R _INA1 and R _INA2 may be chosen to have the same resistance value R _INA .

Also, the inverting input of operational amplifier 412 may be operatively coupled to the output of operational amplifier 412 via resistor _RFA1 . The non-inverting input of the operational amplifier 412 via the resistor _{R FA2} and _{R SA,} may be operably coupled to the output of the operational amplifier 412. Resistance R _FA1 and _{R FA2,} it is preferable to choose to have the same resistance value _{R FA.} The output of the push current source 410 may be positioned between the resistors _{R FA2} and _{R SA.} Accordingly, the push part of the SOS current signal 356 can be supplied between the resistors _{R FA2} and _{R SA.} With such an arrangement, the push portion of the SOS current signal 356 provided by the push current source 410 can be expressed as:

Here, I _PUSH is the current supplied by the push current source 410, and V _SOSCONTROL is the voltage potential of the SOS control signal 302. As can be seen by examining this equation, I _PUSH is proportional to V _SOSCONTROL .

In one embodiment, pull current source 420 can include an operational amplifier 422 operably coupled to resistors R _INB1 , R _INB2 , R _FB1 , R _FB2 , and R _SB in an operational amplifier current source configuration. Input resistors R _INB1 and R _INB2 may be operatively coupled to the inverting input and the non-inverting input of operational amplifier 422, respectively. The inverting input of the operational amplifier 422 can be configured to receive the SOS control signal 354 via the resistor R _INB1 . The non-inverting input of operational amplifier 422 may be operatively coupled to analog ground GND via resistor R _INB2 . The resistors R _INB1 and R _INB2 may be selected to have the same resistance value R _INB .

Also, the inverting input of the operational amplifier 422 can be operatively coupled to the output of the operational amplifier 422 via the resistor _RFB1 . The non-inverting input of the operational amplifier 412 via the resistor _{R FB2} and _{R SB,} may be operably coupled to the output of the operational amplifier 422. Resistance R _FB1 and _{R FB2,} it is preferable to choose to have the same resistance value _{R FB.} The output of the pull current source 420 may be located between the resistor _{R FB2} and _{R SB.} Thus, the pull portion I _PULL of SOS current signal 356 can be drained from by the node between resistors R _FB2 and R _SB . With this configuration, the pull portion I _PULL of the SOS current signal 356 pulled by the pull current source 420 can be expressed as:

Here, I _PULL is a current pulled by the pull current source 420, and V _SOSCONTROL is a voltage potential of the SOS control signal 354. As apparent from the investigation of this equation, I _PULL is proportional to V _SOSCONTROL .

  Additional details regarding the configuration including the push current source and the pull current source are filed on July 1, 2015 "Apparatuses and Methods for Testing Electrochemical Cells by Measuring Frequency Response" (electrochemical cell by measuring frequency response No. 14 / 789,959, entitled Apparatus and Method for Testing. As already mentioned above, the entire disclosure content of the present application is incorporated herein by reference. In one embodiment, the current driver 308 may include a single ended current driver instead of the push-pull current driver of FIG. An example of a single-ended current driver, filed on June 4, 2014, entitled "Apparatuses and Methods for Testing Electrochemical Cells by Measuring Frequency Response" (apparatus and method for testing electrochemical cells by measuring frequency response) U.S. Patent Application Publication No. 2014/0358462 entitled. As already mentioned above, the entire disclosure content of the present application is incorporated herein by reference.

  FIG. 5 shows a schematic diagram of the signal measurement module 310 of the preamplifier 218 of FIGS. 2 and 3. The signal measurement module 310 is said to be suitable for use with not only high voltage systems (e.g. about 300 V) but also mid-range voltage systems (e.g. about 50 V). Other voltage ranges are also conceivable. The signal measurement module 310 comprises a first gain stage (operational amplifier 510) and a plurality of operational amplifiers 510, 520 operatively coupled as additional gain stages (operational amplifiers 520, 530) cascaded from the first gain stage. Including 530. The first gain stage exhibits a first gain (gain A), the second gain stage exhibits a second gain (gain B), and the third gain stage exhibits a third gain (gain C).

  The test battery 205 can be connected to a first amplifier 510 that operates as an attenuator. As shown in FIG. 5, the positive terminal of the test battery 205 can be coupled to the inverting input of the first amplifier 510 (eg, via resistor R1), and the negative terminal of the test battery 205 is connected to the first amplifier 510. It can be coupled to the non-inverting input (eg, via a voltage divider of resistors R2, R3). The output (i.e., output A) of the first amplifier 510 can be returned to the DAS 214 (FIG. 2). The values of resistors R 1, R 2, R 3 and R 4 can be chosen to suit the desired gain A. In one embodiment, the gain A is approximately -0.166. That is, the voltage sent as output A to the DAS 214 can be in the range of about ± 10 V for a 50 V battery. For a 300 volt battery, the voltage delivered to the DAS 214 as output A can be in the range of about ± 60 volts.

  The second amplifier 520 can be used to adjust the battery voltage and set a voltage suitable for comparison with the low back signal received from the DAS 214. Specifically, the second amplifier 520 receives at its inverting input the output (i.e., output A) from the first amplifier 510 (e.g., via resistor R5) and at its non-inverting input A signal can be received (eg, via a voltage divider of resistors R6, R7). The output (i.e., output B) of the second amplifier 520 can be returned to the DAS 214. The values of resistors R5, R6, R7, and R8 can be selected to suit the desired gain B. In one embodiment, the gain B is approximately -20 (e.g., -19, 85). That is, the voltage sent as output B to DAS 214 can be in the range of about ± 200 V for a 50 V battery (assuming a gain A of about −0.166). For a 300 V battery, the voltage sent as output B to DAS 214 can be in the range of about ± 1.2 kV (assuming a gain A of about −0.166).

  The third amplifier 530 can be used to adjust the battery voltage and set a voltage suitable for comparison with the back signal from the DAS 214. Specifically, the third amplifier 530 receives the output from the second amplifier 520 (ie, output B) at its non-inverting input (eg, via a voltage divider of resistors R9 / R10 and R11), At the inverting input, the back signal from DAS 214 can be received (eg, via the voltage divider of resistors R13, R14). The output of the third amplifier 530 (i.e., output C) can be returned to the DAS 214. The values of resistors R9, R10, R11, R12, R13, and R14 can be selected for the desired gain C. In one embodiment, the gain C is approximately +20 (eg, +19.95). That is, the voltage sent as output C to DAS 214 can be in the range of about ± 4 kV for a 50 V battery (gain A is about -0.166 and gain B is about -20) Suppose) For a 300V battery, the voltage sent as output C to DAS 214 can be in the range of about ± 24kV (assuming a gain A of about -0.166 and a gain B of about -20 To do).

  The overall gain of the signal measurement module 310 can be the product of each of the gains A, B, C. That is, when the gain A ≒ −0.166, the gain B ≒ −20, and the gain C ≒ + 20, the overall gain is about +66 (eg, 66.4). Compared to many conventional systems (about 17), the overall gain can be increased, and this gain increase (eg, about 4 times) contributes to the sensitivity improvement and resolution improvement of the signal measurement module 310. can do. By having at least two bias voltage feedback lines in the gain stage of the signal measurement module 310, it can be said that it is possible to safely increase the overall gain.

  Output A, output B, and output C can each be sent to DAS 214 for feedback when generating a back signal. The DAS 214 may be configured to adapt the generation of the back signal in response to the feedback received from Output A, Output B, and Output C. The back signal may be received from DAS 214 at each of the second and third gain stages of signal measurement module 310. In particular, the second amplifier 520 can receive a low buck signal at its non-inverting input and the third amplifier 530 can receive a high buck signal at its inverting input. As a result, the low buck signal is used to determine the voltage that the second amplifier 520 compares to the output (output A) of the first amplifier 510 to produce its output (output B). In addition, the high buck signal is used to determine the voltage that the third amplifier 530 compares to the output (output B) of the second amplifier 520 to generate its output (output C).

  FIG. 6 is a flowchart 600 illustrating a method of operating a battery impedance measurement system in accordance with an embodiment of the present disclosure. The impedance measurement system can operate in auto range mode and measurement mode. The auto-range mode is said to allow the IMD to operate over various batteries that exhibit a wider range of impedance. At operation 610, the IMD can perform an autoranging function on the test battery to determine the current amplitude to use during the measurement mode. At act 620, the IMD can perform measurements on the test battery to determine impedance measurements that can inform the impedance measurement system of the health of the test battery. The processor of the IMD can be configured to control the SOSG to perform autoranging of the current excitation signal prior to entering the measurement mode. As an example, the autoranging of the current excitation signal should be performed after the desired back voltage has been achieved by the signal measurement module of the preamplifier, but before performing the impedance measurement during the measurement mode .

  Referring specifically to operation 610 in view of FIG. 3, SOSG 216 may cause current driver 308 to generate SOS current signal 356 as a pulse of increasing or decreasing amplitude. For example, the first pulse may exhibit a first amplitude, the second pulse may exhibit a second amplitude, the third pulse may exhibit a third amplitude, and so on. In one embodiment, the amplitudes of the pulses may increase sequentially, while in other embodiments the amplitudes of the pulses may start at the maximum and decrease sequentially. In yet other embodiments, the amplitudes may be of different magnitudes, but not necessarily in order. In one embodiment, the sequence of pulses may be performed over one period of the sine wave (eg, 100 Hz). The voltage response to these autoranging pulses can be analyzed by DAS 214 and this voltage response can be used to determine which SOS current level to use during the measurement phase. In one embodiment, the DAS 214 can determine which pulse in the sequence of pulses was the last pulse before voltage clipping occurred in the measurement signal. In one embodiment, the pulse may exceed one cycle of a sine wave higher than 1 Hz and be less than the Nyquist frequency to allow rapid determination of the RMS excitation current. In embodiments employing a time crosstalk compensation (TCTC) method, the RMS excitation may be selected conservatively. This is because saturation in the captured time record can corrupt the impedance measurement.

  With particular reference to operation 620 in view of FIG. 3, processor 212 causes SOSG 216 to generate SOS current signal 356 during its measurement mode based at least in part on the result of the autoranging mode. It is configured to control the current driver 308. In one embodiment, processor 212 may use a set point for SOSG 216 that generated SOS current signal 356 having the largest amplitude prior to voltage clipping of the battery voltage measured during autoranging mode. . Prior art prior art IMDs often have a fixed current level (e.g., 0.5 ARMS), which reduces this fixed current level to safely avoid voltage clipping. Can have a variable current level and increased gain, so that the IMD can operate more closely to its peak performance while avoiding voltage clipping during measurement mode. As a result, the maximum current amplitude possible for the excitation current is not limited to a fixed value that ensures that voltage clipping is avoided, but that the hardware supports (eg 2 RAMS, 3 ARMS, 4 ARMS etc. It should just be limited by). That is, an auto-ranging feature can be used to determine which current amplitude to use during the measurement mode from a range of possible current amplitudes.

  During the measurement mode, a number of different data processing methods can be employed to determine the impedance of the test battery 205 from the electrical signal 206 (FIG. 2). As an example, the data processing method used by DAS 214 is, for example, a US patent entitled "Crosstalk Compensation in Analysis of Energy Storage Devices" (Crosstalk Compensation in Analysis of Energy Storage Devices), issued June 24, 2014. A time crosstalk compensation (TCTC) method may be included, as described in US Pat. No. 8,762,109. In one embodiment, the data processing method used by the DAS 214 is, for example, filed on July 1, 2015, as "Apparatuses and Methods for Testing Electrochemical Cells by Measuring Frequency Response" (electrochemistry by measuring frequency response). The HOST method may be included as described in US patent application Ser. No. 14 / 789,959, entitled Apparatus and Method for Testing Cells. As already mentioned above, the entire disclosure content of the present application is incorporated herein by reference. In one embodiment, U.S. Pat. No. 8,150, issued Apr. 3, 2012, entitled "Method of Detecting System Function by Measuring Frequency Response" (Method of Detecting System Function by Measuring Frequency Response); Fast Add Transformation (FST) method disclosed in US Pat. In one embodiment, the data processing method used by the DAS 214 is issued on January 8, 2013, and is a method of detecting a system function by measuring a "Method of Detecting System Function by Measuring Frequency Response". And the Triad-based Generalized Fast Summation Transformation (GFST) method described in US Pat. The entire disclosure of the above application is incorporated herein by reference. Other methods are also conceivable, including modified TCTC and HOST methods.

  The data processing method can be configured to withstand over-range saturation. For example, time records captured against battery voltage may be examined for signal saturation, and any samples within voltage time records higher or lower than the maximum scale voltage may be discarded. In addition, the same conditions can be applied in the current time record to samples that are discarded because they are higher or lower than the maximum scale current in the current time record. As a result, the data processing method can be configured to compensate for deleted data points.

  As an example, some data processing methods are based on SOS signals with frequency spread that are octave harmonic (eg HOST). In such a HOST method, the frequency spread is harmonic over one decade, such as 1, 2, 3, 4, 5, 7, 9. In one embodiment, the HOST method may alternate between sine and cosine between frequencies. As a result, with harmonic spreading, sine and cosine alternation, an extra level of orthogonality is obtained between the frequencies. In addition, when both voltage and current time recordings are obtained and processed using the HOST method into the frequency domain, the ratio of voltage response to current response at a particular frequency becomes the impedance at that frequency. That is, measurements using the HOST method can be self-calibrating, and both measurements can be made to respond to the same smoothing filter, thus eliminating the need for smoothing filter pre-emphasis.

As discussed above, the HOST method may employ alternating sine / cosine (ASC) summation signals instead of pure SOS signals. If the frequency spread across the measurement data is too fine, the signal to noise ratio (SNR) will be the signal power split between multiple frequencies, which may result in a lower signal to noise ratio for each frequency. For the derivation of these methods, one can assume a given number M and a spread f _{K of} frequency, where f _M ≦ 2000 Hz. For the HOST method, the ASC current signal is used to excite the test battery, which is shown in equation (1).

Here, I _P is the peak current at each frequency, Δt is the sample time step, and I _ASC is the computer generated current. The captured voltage time record is shown in equation (2a) and the captured current time record is represented in equation (2b).

Where R _IO represents an arbitrary DC offset in the current measurement system (account for), I 2 _j is the amplitude of the f 2 _j sine wave frequency, I 2 _{j -1} is the f 2 _{j -1} cosine wave frequency, Φ _{I2 j} is the phase of the f 2 _j sinusoidal frequency, and I I 2 _j-1 is the phase of the f 2 _j-1 cosine frequency.

Here, R _VO accounts for any DC offset in the voltage measurement system, V 2 _j is the amplitude of the f 2 _j sine wave frequency, V 2 _{j -1} is the f 2 _{j -1} cosine wave frequency, Φ _V2j is the phase of the _{f 2j} sinusoidal frequency, Φ _V2j-1 is the phase of the _{f 2j-1} cosine wave frequencies.

  Equations (2a) and (2b) can be solved as equation (3) for generic time records.

  This can be converted to matrix form and further simplified as follows.

here,

And

  Equation (4) can then be used to solve equations (2a) and (2b), so that the battery impedance at the ith frequency can be approximately expressed as:

  Equation (5) operates on samples from the acquisition time record that were discarded when the sample was positive or negative maximum scale voltage or current, where N remaining samples were such that N> (2M + 1) can do. In one embodiment, a second-order Butterworth low pass filter may be selected for the smoothing filter (FIG. 3) so that the transfer function H (s) of the low pass filter can be expressed as:

  In one embodiment, the cutoff frequency of the transfer function H (s) may be selected at 1 Hz or other suitable frequency. The excitation current signal may be selected to have a Nyquist frequency higher than the highest frequency (eg, 2 kHz) in the excitation current signal. By selecting the frequency of the excitation current, the amplitude of the excitation current signal can be selected based on the analysis performed during the autoranging mode. This excitation current signal can then be used in measurement mode, with the gain increase described above with respect to FIG.

  The combination of increased excitation current amplitude and increased gain results in improved sensitivity and resolution over existing IMDs. The sensitivity and resolution improvement can be said to be about 10 to 15 times based on the preliminary inspection. As a result of the features discussed herein, the IMD is configured to measure the internal impedance of a high power battery cell exhibiting low impedance (eg, between about 1 milliohm and 5 milliohms, less than about 1 milliohm, etc.) While, high resolution (eg, at least about 0.01 milliohms) and rapid measurement (eg, 10 seconds or less) can be maintained. Such characteristics are an improvement over conventional methods using IMD (limited in resolution to low impedance) and those using electrochemical impedance spectroscopy (slow measurement).

Additional embodiments include the following.
Embodiment 1 An impedance measuring device, a current driver configured to generate an excitation current signal applied to the test battery in response to the control signal, and a processor operably coupled to the current driver, the autoranging device The processor configured to generate the control signal during the mode and the measurement mode, wherein the autoranging mode applies the excitation current signal to the test battery over a plurality of different amplitudes, the excitation current at each amplitude The response to the signal is measured and the measurement mode applies an excitation current signal to the test battery with an amplitude responsive to the result of the autoranging mode.

  Embodiment 2. The impedance measuring device of Embodiment 1 further includes a preamplifier including a current driver and a signal measuring module configured to measure an electrical signal in response to an excitation current signal applied to the test battery.

Embodiment 3. In the impedance measuring device of embodiment 1 or 2, the current driver exhibits an overall gain greater than about 20.
Embodiment 4. In the impedance measurement device of embodiment 3, the overall gain is greater than about 60.

  Embodiment 5. In any of the impedance measuring devices of embodiments 2-4, the current driver includes at least three cascaded gain stages, and from each cascaded gain stage to determine a plurality of buck voltages to be returned from the processor to the current driver. The output of is fed back to the processor.

  Embodiment 6. In the impedance measuring device of embodiment 5, the at least three cascaded gain stages comprise a first gain stage exhibiting a first gain of approximately -0.166, a second gain stage exhibiting a second gain of approximately -20, and And a third gain stage exhibiting a third gain of twenty.

  Embodiment 7. The impedance measuring device according to any of the embodiments 1-6, wherein the current driver is configured to generate at least one of a sine wave sum (SOS) current signal or an alternating sine wave / cosine wave (ASC) sum signal Be done.

  Embodiment 8. In any of the impedance measuring devices of Embodiments 1 to 7, the current driver includes a differential current source including a pull-up current source and a pull-down current source operably coupled to the test battery.

  Embodiment 9. An impedance measurement system, comprising: a test battery; and an impedance measurement device operably coupled to the test battery, the impedance measurement device including a current driver and a signal measurement module operably coupled to the test battery. A preamplifier including: a current control signal generator operatively coupled to the preamplifier; a data acquisition system operatively coupled to the preamplifier; a processor operatively coupled to the current control signal generator and the data acquisition system And the processor controls the current control signal generator to send a current control signal to the preamplifier during autoranging mode to cause the current driver to generate an excitation current signal exhibiting a range of amplitudes, Check bar from signal measurement module during range mode The data acquisition system is controlled to analyze the response of the Terri, and the current control signal is sent to the preamplifier during measurement to at least partially analyze the response of the test battery during the autoranging mode Controlling the current control signal generator to cause the current driver to generate an excitation current signal exhibiting a selected amplitude, and analyzing the test battery response from the signal measurement module during the measurement mode to determine the test battery impedance Configured to control the data acquisition system to make a determination.

Embodiment 10. In the impedance measurement system of embodiment 9, the battery includes one or more energy storage cells.
Embodiment 11. In the impedance measurement system of embodiment 9 or 10, the data acquisition system includes an impedance calculation module that executes a data processing method to determine the impedance of the test battery, and the data processing method comprises: voltage time recording or current time It is configured to capture at least one of the records and discard samples that are within the voltage or current time record higher or lower than the maximum scale for the respective time record.

Embodiment 12. The impedance measurement system according to any of embodiments 9 to 11, wherein the data acquisition system comprises an impedance calculation module for performing a data processing method to determine the impedance of the test battery, the data processing method comprising time crosstalk compensation 14. The embodiment selected from the group consisting of: (TCTC) method, harmonic orthogonal synchronous transform (HOST) method, fast additive transform (FST) method, and generalized fast additive transform (GFST) based on triads. The impedance measuring system of any of embodiments 9-12, further comprising a remote computer operably coupled to the impedance measuring device, the remote computer controlling the impedance measuring device, the impedance measuring device Configured to receive impedance data from the

  Embodiment 14. In any of the impedance measurement systems of embodiments 9 to 13, the preamplifier further includes a smoothing filter operably coupled between the current control signal generator and the current driver.

  Embodiment 15. The impedance measurement system according to any of the embodiments 9-14, wherein the excitation current signal is a sum of sine (SOS) current signal or alternating sine / cosine (ASC) for each of the autoranging mode and the measuring mode. B) including at least one of the summation signals.

  Embodiment 16: In any of the impedance measurement systems of embodiments 9-15, the test battery exhibits an internal impedance of between about 1 milliohm and 5 milliohms.

  Embodiment 17: The impedance measurement system according to any of the embodiments 9-16, wherein the impedance measurement device exhibits a resolution of at least 0.01 milliohms with a measurement time of about 10 seconds or less.

Embodiment 18: 18. An impedance measuring system according to any of embodiments 9 to 17, further comprising a vehicle including a test battery.
Embodiment 19: In the impedance measurement system of embodiment 18, the vehicle further includes an impedance measurement device.

  Embodiment 20. A method of measuring the impedance of a test battery, comprising applying to the test battery an excitation current signal comprising a plurality of pulses exhibiting different amplitudes during the autoranging mode, and testing the response to the excitation current signal over the plurality of different amplitudes. Measuring an electrical signal from the battery and applying an excitation current signal exhibiting a fixed amplitude to the test battery during the measurement mode, the fixed amplitude being at least partially measured during the autoranging mode Measuring the electrical signal from the test battery in response to the excitation current signal exhibiting a fixed amplitude during the measurement mode and steps determined based on the analysis of the measured electrical signal to determine the internal impedance of the test battery And step.

  Embodiment 21. In the method of embodiment 20, the fixed amplitude corresponds to an amplitude at least one pulse earlier than when it is determined that voltage clipping has occurred in the electrical signal during the autoranging mode within the plurality of pulses.

  Embodiment 22. 22. The method of embodiment 20 or 21 wherein applying the excitation current signal to the test battery comprises applying an excitation current to the test battery exhibiting an average mid-range voltage of between about 40V and 60V, or between about 250V and 350V. Applying a signal.

  While specific exemplary embodiments have been described above in connection with the drawings, it will be appreciated by those skilled in the art that the embodiments encompassed by the present disclosure are not limited to the embodiments explicitly shown and described above. And will be appreciated and appreciated. On the contrary, with respect to the embodiments described herein, many additions, deletions, etc., without departing from the scope of the embodiments encompassed by the present disclosure and including legal equivalents, as claimed in the following , And can also make changes. In addition, features from one disclosed embodiment may be combined with features of other disclosed embodiments and still be encompassed by this disclosure.

Claims (22)

An impedance measuring device,
A current driver configured to generate an excitation current signal applied to the test battery in response to the control signal;
A processor operably coupled to the current driver, the processor configured to generate the control signal during an autoranging mode and a measurement mode;
Including
The autoranging mode applies the excitation current signal to the test battery over a plurality of different amplitudes and measures the response to the excitation current signal at each amplitude;
An impedance measuring device, wherein the measuring mode applies the excitation current signal to the test battery with an amplitude responsive to the result of the autoranging mode.   The impedance measuring device according to claim 1, further comprising a current driver and a signal measuring module configured to measure an electrical signal in response to the excitation current signal applied to the test battery. Impedance measurement devices, including:   The impedance measuring device according to claim 1 or claim 2, wherein the current driver exhibits an overall gain greater than about 20.   The impedance measuring device of claim 3, wherein the overall gain is greater than about 60.   The impedance measuring device according to claim 1 or 2, wherein the current driver comprises at least three cascaded gain stages, each cascaded to determine a plurality of buck voltages to be returned from the processor to the current driver. An impedance measuring device, wherein the output from the gain stage is fed back to the processor.   6. The impedance measuring device of claim 5, wherein the at least three cascaded gain stages comprise a first gain stage exhibiting a first gain of approximately -0.166 and a second gain stage exhibiting a second gain of approximately -20. And a third gain stage exhibiting a third gain of about 20.   The impedance measuring device according to claim 1 or 2, wherein the current driver is configured to generate at least one of a sine wave sum signal (SOS) current signal or an alternating sine wave / cosine wave (ASC) sum signal. Impedance measurement device.   The impedance measuring device according to claim 1 or claim 2, wherein the current driver comprises a differential current source comprising a pull-up current source and a pull-down current source operably coupled to the test battery. Impedance measurement device. Impedance measurement system,
Inspection battery,
An impedance measuring device operably coupled to the test battery;
Including
The impedance measuring device is
A preamplifier including a current driver and a signal measurement module operatively coupled to the test battery;
A current control signal generator operatively coupled to the preamplifier;
A data acquisition system operatively coupled to the preamplifier;
A processor operably coupled to the current control signal generator and the data acquisition system;
And the processor includes
Controlling the current control signal generator to send a current control signal to the preamplifier during an autoranging mode to cause the current driver to generate an excitation current signal exhibiting a range of amplitudes;
Controlling the data acquisition system to analyze the test battery response from the signal measurement module during the autoranging mode;
An excitation current signal exhibiting a selected amplitude based on transmitting the current control signal to the preamplifier during measurement to at least partially analyze the response of the test battery during the autoranging mode; Control the current control signal generator to generate a current driver,
Controlling the data acquisition system to analyze the response of the test battery from the signal measurement module during the measurement mode to determine the impedance of the test battery;
As configured, the impedance measurement system.   The impedance measurement system of claim 9, wherein the battery comprises one or more energy storage cells.   The impedance measurement system according to claim 9, wherein said data acquisition system comprises an impedance calculation module for performing a data processing method to determine the impedance of said test battery, said data processing method comprising: voltage time recording or current time An impedance measurement system configured to capture at least one of the recordings and discard samples that are within a voltage or current time recording higher or lower than the maximum scale for the respective time recording.   The impedance measurement system according to any one of claims 9 to 11, wherein said data acquisition system comprises an impedance calculation module for performing a data processing method to determine the impedance of said test battery, said data processing method Is selected from the group consisting of: time crosstalk compensation (TCTC) method, harmonic orthogonal synchronization transform (HOST) method, fast additive transform (FST) method, and generalized fast additive transform (GFST) method based on triads Impedance measurement system.   The impedance measuring system according to any one of claims 9 to 11, further comprising a remote computer operably coupled to the impedance measuring device, the remote computer including the impedance measuring device. An impedance measurement system configured to control and receive impedance data from the impedance measurement device.   The impedance measuring system according to any one of claims 9 to 11, wherein the preamplifier further comprises a smoothing filter operatively coupled between the current control signal generator and the current driver. Impedance measurement system.   12. The impedance measurement system according to any one of claims 9 to 11, wherein the excitation current signal is a sine wave sum (SOS) current signal or an alternating sine for each of the autoranging mode and the measuring mode. An impedance measurement system comprising at least one of a wave / cosine wave (ASC) summation signal.   The impedance measurement system according to any one of claims 9 to 11, wherein the test battery exhibits an internal impedance of between about 1 milliohm and 5 milliohms.   17. The impedance measuring system of claim 16, wherein the impedance measuring device exhibits a resolution of at least 0.01 milliohms with a measurement time of about 10 seconds or less.   The impedance measuring system according to any one of claims 9 to 11, further comprising a vehicle including the inspection battery.   The impedance measurement system of claim 18, wherein the vehicle further comprises an impedance measurement device. A method of measuring the impedance of the test battery,
Applying to the test battery an excitation current signal comprising a plurality of pulses exhibiting different amplitudes during the autoranging mode;
Measuring an electrical signal from said test battery responsive to said excitation current signal over said plurality of different amplitudes;
Applying an excitation current signal exhibiting a fixed amplitude to the test battery during a measurement mode, the fixed amplitude at least partially for analyzing the electrical signal measured during the autoranging mode Step set based on
Measuring an electrical signal from the test battery in response to an excitation current signal exhibiting the fixed amplitude during the measurement mode to determine an internal impedance of the test battery;
Test battery impedance measurement methods, including:   21. The method of claim 20, wherein the fixed amplitude is at least one pulse earlier in the plurality of pulses than when it is determined that voltage clipping has occurred in the electrical signal during the autoranging mode. The corresponding way. 22. The method of claim 20 or 21, wherein applying the excitation current signal to the test battery exhibits an average mid-range voltage of between about 40V and 60V, or between about 250V and 350V. Applying the excitation current signal.

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